Science for the Citizen is partly written for the large and growing number of intelligent adults who realize that the Impact of Science on Society is now the focus of genuinely constructive social effort. It is also written for the large and growing number of adolescents, who realize that they will be the first victims of tie new destructive powers of science misapplied. Since it is the first British handbook to Scientific Humanism, it has, inevitably, the glaring faults of any new thing. Education segregates the scientific specialist from those who study problems of government and social welfare. So, like anyone else who in this generation might have attempted a task so ambitious, I have had to re-educate myself in the process of writing it.